Long term observations of biomass burning aerosol over Warsaw by means of multiwavelength lidar

High quality lidar measurements of PollyXT operating at the University of Warsaw in the years 2013-2022 were analyzed to present a comprehensive optical characterization of biomass burning aerosols over Warsaw. The directions of the aerosol inflows were analyzed by dividing advection cases into four types, according to the area of origin: Western Europe, Eastern Europe, the Iberian Peninsula, and North America. It was shown that optical properties of smoke vary in each of these types, and emphasized that aerosol aging processes are important. It was found that as aerosol's age increases, there is more backscattering and less extinction at 355 nm in relation to 532 nm. The analysis of the lidar ratio demonstrated that the main changes of the aging process were observed in the UV spectra.